Red-violet to blue vat-dyes and process of making same.



UNITED STATES PATENT ornron I GADIENT ENGI, or BASEL, SWITZERLAND, ASSIGNOR TO THE FIRM or SOCIETY or CHEMICAL INDUSTRY IN BASLE, on BASEL, SWITZER- .LAND

RED-VIOLET T ,BLUE VAT-DYES ANDIPROCESS-OFEMAKING SAME} ratenteu lVLaron-QG 1907.

Application filed January 9, 1907. Serial No. 351,444;

To all whom it may concern:

Be it known that I, GADI'ENT ENGII, chemist and doctor of-plil osophy, a citizen of the Swiss Republic, and a resident of Basel,

Switzerland, have invented new and useful Red-Violet to Blue Vat-Dyeing Dyestuffs and a Process for the Manufacture of the Same, of which the following is a full, clear,

and exact description.

In my United States Letters Patent No.

836,309, dated November 20, 1906, I have described the manufacture of red-violet to violet-blue vat-dyeing dyestufls by condensing al ha-oxythiona )hthene (thioindoxyl) with a pha-isatinaryhds of the general formula Since I have found that these dyestuffs can be transformed into new more valuable products by introducing a halogen into its molecule.- The thus-resulting halogen derivatives possess relatively to the dyestuif employed as parent materials the advantage of a greater fastness to light and of more lively tints.

The invention is illustrated by the following example: Four parts, by weight, of the product resulting from the condensation of one molecule alpha-oxythionaphthene (thioindoxyl) with one molecule alpha-isatinanilid in presence of nitrobenzene are suspended into forty parts of nitrobenzene. To this suspension are added six to eight arts of bromin, and the mixture is heate in the 7 course of about half an hour in a refluxapparatus gradually to a gentle ebullition. The mass is further heatedfor about one and onehalf hours. The beautiful blue-violet solution is then allowed to cool, and the product of reaction is separated by filtration, washed with alcohol, and dried. The new dyestuff constitutes brilliant violet small crystals soluble in concentrated sulfuric acid with a blue coloration. By diluting this. sulfuricsolution with water violet-blue flocks are recipitated. Fuming sulfuric acid disso ves I the dyestufi' with formation of a solution showing a bright-blue coloration, which is not 836,309 and resulting from the condensation of salicylthioacetic acid or alpha-oxytlnonaphthene (thioindoxyl) with alpha-isatinarylids. For instance, the product result-- ing from the condensation of two molecules alpha-oxythionaphthene with one molecule al )ha-isatinanilid yield a bromin derivative dyeing unmordanted cotton from an alkaline vat bright blue-violet tints, while the bromin derivative of the product resulting from the condensation of one molecule alphaoxythionaphthene with one molecule alpha isatinanilid in acetic anhydrid dyes unmordanted cotton violet tints.

What I claim is- 1. The herein-described process for the manufacture of red-violet to blue vat-dyeing dyestuffs, by treating with a halogen in pres. ence of an indifferent diluent the products obtained by the condensation of alpha: oxythionaphthene (thioindoxyl) with alphaisatinarylids of the general formula 2. As new products, the halogenated redviolet to'blue vat-dyeing dyestuffs derived from the condensation products of alphaoxytlnonaphthene (thioindoxyl) with alphaisatinarylids, the said dyestuffs being sparingly soluble in alcohol, sufficiently soluble in hot benzene and easily soluble in -nitrobenzene with a bluewislet 'coloratien, giving 7 myrname, this 19th day 0f December, 1906, [with sulfuric acid blue sghllationsgrom which a in the presence of two subscribing witnesses; -i'eci itate is se mm edition of i I f 1 31 16 diesolviiigin fum ing sulfuric acid i GADHERT 5 with a bright-0111a coloration which is not f Witnesses:

changed on heating. GEQ. GIFFORD,

- In Witness whereof I have hereunto signed I'AMAND RIITER 

